Active grinding media for processing samples

ABSTRACT

An active/resilient grinding media inside a tube containing a sample is oscillated rapidly by a homogenizer so that the active media is driven in a first direction until it impacts a first end of the tube, which causes it to deform and store an energy charge as it decelerates and stops, and it then accelerates rapidly in the second opposite direction under the discharging force of the stored energy toward the opposite second end of the tube. This cycle of the active media decelerating/charging and then discharging/accelerating is repeated throughout the entire oscillatory processing of the sample. The result is much higher velocities of the active media and therefore much greater impact forces when the sample and active media collide, producing increased efficiency in disruption and size-reduction of the sample particles.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the priority benefit of U.S. Provisional PatentApplication Ser. No. 62/980,638, filed Feb. 24, 2020, and U.S.Provisional Patent Application Ser. No. 62/879,087, filed Jul. 26, 2019,which are hereby incorporated herein by reference.

TECHNICAL FIELD

The present invention relates generally to laboratory devices andaccessories for homogenizing sample materials, and particularly to suchlaboratory homogenizing devices, sample tubes, and grinding media.

BACKGROUND

Homogenization involves disaggregating, mixing, resuspension, oremulsifying the components of a sample using a high-shear process withsignificant micron-level particle-size reduction of the samplecomponents. Homogenization is commonly used for a number of laboratoryapplications such as creating emulsions, reducing agglomerate particlesto increase reaction area, cell destruction for capture of DNA material(proteins, nucleic acids, and related small molecules), DNA and RNAamplification, and similar activities in which the sample is bodilytissue and/or fluid, other organic material, or another substance.

One type of laboratory homogenization equipment is bead milling devices.In traditional bead milling devices, the sample is contained within atube along with grinding media to grind, disrupt, or reduce the particlesize of the sample upon being driven through an oscillatory motion atextremely high velocities. Typically, this grinding media is comprisedof flow-interfering beads (e.g., pellets or particles) made of amaterial (e.g., glass, ceramic, metal, mineral, or plastic) that issignificantly harder than the sample being processed and subject toforces and accelerations from impacting the ends of the tube as itoscillates, causing repeated impacts between media and sample. Whileconventional grinding media, and homogenization methods using them, havetheir benefits, further improvements in this technology are desirable.

Accordingly, it can be seen that needs exist for improvements ingrinding media and methods for processing samples. It is to theprovision of such solutions that the present invention is primarilydirected.

SUMMARY

Generally described, the present invention relates to anactive/resilient grinding media held inside a tube containing a sample,with the tube oscillated rapidly by a homogenizer so that the activemedia is driven in a first direction until it impacts a first end of thetube, which causes it to deform and store an energy charge as itdecelerates and stops, and it then accelerates rapidly in the secondopposite direction under the discharging force of the stored energytoward the opposite second end of the tube. This cycle of the activemedia decelerating/charging and then discharging/accelerating isrepeated throughout the entire oscillatory processing of the sample. Theresult is much higher velocities of the active media and therefore muchgreater impact forces when the sample and active media collide,producing increased efficiency in disruption and size-reduction of thesample particles.

The specific techniques and structures employed to improve over thedrawbacks of the prior art and accomplish the advantages describedherein will become apparent from the following detailed description ofexample embodiments and the appended drawings and claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram of a homogenizing system according to anexample embodiment, showing a homogenizer holding four sample tubes,with one of the tubes holding an active grinding media.

FIG. 2 is a longitudinal cross-sectional side view of the tube andactive grinding media of FIG. 1 , showing an unprocessed sample withinthe tube.

FIG. 3 is a transverse cross-section end view of the tube and activegrinding media of FIG. 12 , with the sample not shown for clarity ofillustration.

FIGS. 4-13 show the tube, active grinding media, and sample of FIG. 2used in a homogenizing process, with each figure showing a sequentiallyadvanced position during the homogenizer-driven reciprocating motion ofthe tube, sample, and active grinding media.

FIGS. 14 a -26 show additional active grinding media according tovarious respective example embodiments, with FIGS. 14 a and 14 b beingside and end views, respectively, with FIGS. 15-23 being side views, andwith FIGS. 24-26 being perspective views.

DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS

The present invention relates to improved homogenization processingusing a homogenizer, a sample tube, and an innovative resilient grindingmedia. The resilient grinding media stores and releases energy, andimpacts the sample while enabling the sample to flow past it, duringeach oscillation cycle inside the tube to dramatically improveprocessing of the sample. As such, the resilient grinding media arereferred to herein as an “active” (or “dynamic”) media (aka“energy-storage devices”) because the storage and release of energycauses the grinding media to travel at speeds and accelerations greater(typically much greater) than the tube and/or the sample, and to changeoscillatory directions within the tube sooner (typically much soonergreater) than the sample, to deliver greater (typically much greater)impact forces to the sample. This produces a dramatic effect andimprovement in the processing of the sample. This is in contrast toconventional grinding media, which are intentionally made of extremelyrigid/hard materials that in homogenizing use absorb no (or relativelynegligible) energy in order to maximally transfer their kinetic energyto the sample material being processed (e.g., when multiple of thegrinding media impact each other and/or the tube end and between themshear the sample), which therefore are only accelerated as greatly asthe tube is accelerated when they together reverse direction in theiroscillatory motion, and which therefore change oscillatory directionstogether with the sample being processed. Because of thesecharacteristics of conventional grinding media, they can be referred toas “passive” media.

A few preliminary definitions are as follows. “Homogenizing” and“processing” as used herein are intended to be synonymous and broadlyconstrued to mean particle-size reduction of a sample by high-sheardisaggregating, mixing, resuspending, and/or emulsifying (i.e.,separation, not destruction) of the components of the sample by anaxially/linearly reciprocating/oscillating shaking motion of the tubescontaining the samples (sometimes referred to as “milling”).

“Homogenizer” (aka “homogenizing device”) as used herein is intended tobe broadly construed to include any type of device thathomogenizes/processes samples, including conventional high-poweredshaker-mill (aka bead-mill) laboratory homogenizers (e.g., commerciallyavailable from OMNI International, Inc. under the brand name BEADRUPTOR) and other laboratory equipment that is operable forhomogenizing.

“Sample” as used herein is intended to be broadly construed to includeany type of material that can be homogenized and for whichhomogenization could be useful, such as but not limited to human and/ornon-human bodily fluid and/or tissue (e.g., blood, bone-marrow cells, acoronary artery segment, or a piece of an organ), other organic matter(e.g., plants or food), and/or other chemicals.

And “tube” is intended to be broadly construed to include any closablevessel or container that can hold a sample during homogenization and isnot limited to conventional cylindrical hard-plastic vials (“diameter”as used herein is thus also intended to include another transversechamber dimension for a non-cylindrical tube).

In various aspects, the invention relates to an active grinding mediaprovided by itself for use with a sample tube and a homogenizer, anactive grinding media and a tube provided together for use with ahomogenizer, or a complete assembly including an active grinding media,a sample tube, and a homogenizer. In another aspect, the inventionrelates to a set of a plurality of the active grinding media withdifferent configurations for customized selection of a particular one ofthe active grinding media for homogenizing a particular sample. And inyet another aspect, the invention relates to methods of homogenizing asample by using a tube including an active grinding media.

The active grinding media has a grinding body made of a resilientlydeformable (aka resilient) material such that it deforms and storesenergy upon impacts, and in response it resiliently returns to itsneutral form/shape/state as it discharges and releases the storedenergy. In particular, the resilient active grinding media reciprocateswithin a longitudinal-axis processing tube that also contains a samplematerial and that is held and oscillated through an axiallyreciprocating motion by a homogenizing device. As such, when the tube isdriven through the oscillatory motion, the active grinding media isdriven in a first direction until it impacts a first end of the tube,which causes it to deform and store an energy charge as it deceleratesand stops, and it then accelerates rapidly in the second oppositedirection under the discharging force of the stored energy toward theopposite second end of the tube. This cycle of the active grinding mediadecelerating/charging then discharging/accelerating is repeatedthroughout the entire oscillatory processing of the sample. The resultis much higher velocities of the active grinding media and thereforemuch greater impact forces when the sample and active grinding mediacollide. This in turn results in dramatically shorter processing timeswith less heat generated, both very important benefits to sampleprocessing.

In typical embodiments, the resiliently deformable material is a metal(e.g., spring wire), plastic, rubber (e.g., hard rubber), otherresilient material, or a composite. In some embodiments, the entiregrinding body is made of the resilient material, with the materialselected with a resiliency so that the grinding body deforms uponimpacts with the tube ends (and resiliently returns/undeformsafterwards) but does not deform (or only negligibly does so) uponimpacts with the sample material. As such, the material selection for agiven homogenizing process can be based in part of the rigidity/hardness(or resiliency/softness) of the tube to be used as well as the mass anddensity of the sample to be processed. In other embodiments, a portionof the grinding body is made of the resilient material (selected forenergy storage and release) and at least one other portion of thegrinding body is made of a rigid material (selected for transferringkinetic energy to the sample). For example, in some embodiments thegrinding body includes two longitudinally opposite end portions (withimpact surface areas) that are made of a rigid material and alongitudinally intermediate portion (between the ends) that is made ofthe resilient material.

The resilient material (and optional additional rigid material) of thegrinding body can be further selected with a resiliency (as well as amass, density, size and shape) so that in use it has a sufficiently highacceleration and velocity that it accelerates and travels faster thanthe tube and faster than the sample. In particular, the active grindingmedia has an average speed (including relatively higher acceleration andvelocity initially after discharging at the tub first end and relativelyslower acceleration and velocity later just before impacting the tubeopposite second end) that is greater than the average speed of the tubeor sample. As such, the active grinding media typically impacts the tubeends before the tube changes directions (i.e., momentarily stops andreverses direction from the first direction to the second oppositedirection in its oscillatory reciprocating motion cycle), or at leastbefore the sample impacts the tube ends. In other embodiments, theactive grinding media is configured and selected so that it impacts thetube ends at the same time or after the tube changes directions,depending for example on the sample being processed (e.g., some sampletypes and volumes provide more resistance to motion of the activegrinding media), the homogenizer speed setting (e.g., some activegrinding media of greater mass might require slower oscillatory speeds),the tube (inner/chamber) length (and thus the available travel of theactive grinding media), and the tube travel distance/length (as drivenby the travel stroke of the particular homogenizer being used).

Because of the use of the resilient material, the active grinding mediahas a higher acceleration immediately after its travel directionreversal (from the first direction to an opposite second direction) thanjust before its impact with the tube end. Also, because the activegrinding media has a greater average velocity (and greater mass) thanthe sample, this direction reversal of the active grinding media occurswhile at least some pieces of the sample are still traveling in thefirst direction. The combination of these two features results in higherimpact velocities and greater impact forces transmitted from the activegrinding media to the sample. This is because the active grinding mediais traveling in the second direction when it impacts at least some ofthe sample pieces still moving in the opposite first direction, so therelative speed of the active grinding media (relative to the sampletraveling in the opposite direction) is greater than the actual speed ofthe active grinding media. And this is further because the activegrinding media is accelerating in the second direction when it impactsat least some of the sample pieces still moving in the opposite firstdirection, with this acceleration increasing the force that the mass ofthe active grinding media impacts and imparts to the sample.

In addition, the configuration and (resilient) material of the activegrinding are typically selected to have a total mass that is greaterthan the mass of the sample being processed, though it can be less thanthe sample mass in some cases. For example, the active grinding mediabody has a mass that is typically at least about 75% of the mass of thesample and typically no more than about 200% of the sample mass. Agreater-mass active grinding media (e.g., 100%-200%) is generallybeneficial for processing relatively harder samples (e.g., bone), and alower-mass active grinding media (e.g., 75%-100%) is generallybeneficial for processing relatively softer samples (e.g., muscle).

The active grinding media is typically provided with a single grindingbody configured for use by itself to process the sample in the tube,that is, with only one active grinding media in the tube with the sampleat a time. Because of the single grinding body/mass traversing the tube,higher impact forces are imparted to the sample being processed(relative to a number of conventional smaller passive media particles).Also, with only a single grinding body in the tube at a time, it onlycontacts the tube and the sample (so there is no contacting of multiplegrinding beads against each other).

In such single-body embodiments, the active grinding media is typicallyis elongate with an axial orientation relative to the tube andconfigured with proportions relative to the tube that promote aprimarily axial orientation and translational movement of the activegrinding media within the tube in order to maximize the impact forces itdelivers to the sample. In particular, the active grinding media has anaxial length that is the same as or greater than the inside diameter ofthe processing tube in order to prevent it reorienting to aperpendicular position with its axis perpendicular to the tube axisduring translation within the tube. In example embodiments, the tube hasan inner diameter of about 0.2 inches to about 2.0 inches, with theactive grinding media selected with an axial length that is greater thanthe inner diameter of the corresponding tube it is to be used with. Inthis way, the active grinding media is maintained in a generally axialorientation relative to the tube axis during processing use. While theactive grinding media in some embodiments might reorient somewhat andtraverse the tube with its axis not necessarily parallel to the tubeaxis, it is nevertheless maintained oriented within an acute angle ofthe tube axis because of mechanical interference due to the activegrinding media being too long to reposition to perpendicular to the tubeaxis. Because the active grinding media is ensured to be in itsgenerally axial orientation when it impacts the tube ends, it can beused with longer tubes (relative to with conventional passive grindingmedia) operating at lower oscillation amplitudes (relative to withconventional passive grinding media). Also, the active grinding medialength is selected, relative to the tube length and the homogenizerstroke distance, to ensure that the active grinding media impacts theends of the tube at each oscillation. With the active media length, thetube length, the stroke length, and the spring constant selected toaccommodate the full compression of the active media at each end of thestroke, the active media performs as desired.

In addition, the active grinding media body typically has a maximumwidth (transverse to the axial length) that is smaller than the insidediameter of the processing tube but large enough to promote the desiredprimarily axial translational movement (i.e., to limit the lateral andangular movement of the grinding body in the tube during oscillation bylimiting a maximum angle from axial of the active grinding media body).In this way, there are fewer glancing impacts of the tube sidewalls bythe active grinding media, which thereby maintains its momentum and thehigh impact forces it can deliver to the sample. Conventionalhomogenizing tubes have an inner/chamber diameter of about 0.2 inches toabout 2.0 inches, and an inner/chamber length of about 0.2 inches toabout 6.0 inches. In example embodiments, the active grinding media hasa maximum width that is typically about 50% to about 80% of the tubeinner diameter (e.g., about 0.1 inches to about 1.6 inches), for exampleabout 65%. Also, the axial length of the active grinding media istypically enough greater than the tube inner diameter to promote thedesired primarily axial translational movement. In example embodimentsthe active grinding media has a length that is typically about 100% toabout 400% of the tube inner diameter (e.g., about 0.2 inches to about8.0 inches), for example about 250%. The axial length of the activegrinding media can also be up to about 90% of the tube length, whichallows sufficient oscillatory travel within the tube for processing thesample.

Furthermore, the active grinding media body can be provided in a numberof different shapes/forms. For example, the active grinding media bodycan be a coil compression spring with a central axial flow-through bore(annular space) and with end impact surfaces (annular) that contact thetube ends. In other embodiments, the active grinding media body is madeof a resilient material in the form of a solid or hollow bead, ball, orblock, a hollow spheroid with a peripheral shell made of a screen, mesh,or spring material, or another regularly or irregularly shaped solid,hollow, or perforated structure. For embodiments in which the grindingbody does not have an axial orientation (e.g., spheroid shapedembodiments), the impact end surfaces (discussed below) are not fixedand instead are defined based on the particular orientation at the timeof each impact).

The active grinding media body also typically has internal and/orexternal flow-through openings that provide a passageway for pieces ofthe sample to pass through or around the grinding body as they areoscillated at very high speeds. Such flow-through openings can includethe axial internal annular space through a coil compression spring.Other embodiments include flow-through openings provided by internalpores, shafts, or other passageways, by external/surface notches orchannels, by both internal and external flow-through openings, and/or bylateral flow-through openings connecting internal and externalflow-through openings. For active grinding media having an axial travelorientation, the flow-through openings are typically axially arranged inthe grinding body (including not just linear but also sinusoidal,undulating, and other regular and irregular passageway shapes andsurfaces). Still other such flow-through openings can be formed by thegaps in a screen or mesh material forming a peripheral shell of a hollowgrinding body.

In other embodiments, the active grinding media has multiplecomponents/bodies for example including a non-resilient materialcomponent coupled to a resilient-material component, with thenon-resilient material component being for example a solid mass or“slug” of material (e.g., with no flow-through openings) for a goodimpact surface area, and with the resilient-material component being forexample a spring or other energy storage device (e.g., with flow-throughopenings).

In some embodiments, the active grinding media body has across-sectional impact area (e.g., transverse to the axial/longitudinaloscillatory direction) that is relatively small (relative to thecollective cross-sectional impact surface area of numerous smallerconventional passive grinding media, i.e., not relative to the entireexposed surface area). For example, the cross-sectional impact area ofthe active grinding media can be less than about 0.035 in²/gram (basedon the mass of the active grinding media). Because of the increasedacceleration and thus impact forces of the active grinding media, thesmaller cross-sectional impact area can produce the same or betterhomogenizing effect. Also, the smaller cross-sectional impact surfacearea results in greater pressures and thus even greater forcestransferred to the sample, thereby focusing these higher accelerationsand forces on the sample being processed (i.e., the impact forces areeven greater because the cross-sectional area is reduced).

The active grinding media can generate even further increased impactforces on the sample by selecting properties of the active grindingmedia body (e.g., spring constant, mass, and cross-sectional impactarea) based on the oscillatory frequency the homogenizer is to beoperated at. Thus, the pressure of the impacts can be fine-tuned byselectively choosing properties of the active grinding media to provideincreased effectiveness and efficiency of the processing.

The active grinding media can be used with tubes not designed forcontaining as high processing forces (e.g., less-robust tubes intendedfor slower oscillatory speeds), because the impact between the activegrinding media and the tube ends is cushioned as the active grindingmedia deforms/compresses (the active grinding media absorbs the energyto charge itself instead of that energy being transmitted to the tubeend), thereby reducing the forces on the tube ends from impacts by theactive grinding media. In other words, use of the active grinding mediaenables oscillating the samples in tubes at higher speeds than the tubescould be safely oscillated at with conventional passive grinding media.Also, instead of using reinforced tubes (with thicker sidewalls and endsto withstand bead beating forces) as is done when using conventionalpassive grinding media, use of the active grinding media enables use ofconventional/standard unreinforced tubes.

Active grinding media provided in some forms, for example coilcompression springs, have an annular cross-sectional impact area at eachend. For use with such embodiments, the tube end (including one integralend and one end cap) can be selected with a corresponding annularportion that is rigid (to withstand the grinding body impacts at the endof the range of motion) and with the central portion that is less rigid(that cannot withstand the impacts). In some embodiments, the tubeendcap has a center portion that is made of a material that ispuncturable (e.g., by syringe) to enable for post-processing samplerecovery without unscrewing and removing the cap.

For embodiments of the active media in the form of coil compressionsprings, the spring constant (defining the rate of compression) istypically selected to be proportional to the acceleration of the tubecontaining the active media and sample. In particular, the homogenizercan be set at a selected speed (also the tube oscillation speed)(withexample homogenizers having speed settings between about 0.1 m/s andabout 6.0 m/s) based on the type of sample to be processed, and then thespring constant can be selected so that the spring fully compresses ateach impact with the tube ends for the selected tube oscillation speed.The spring constant is also relevant to the process of storing andreleasing energy during the deceleration and acceleration of the tube,by which the resultant velocity causes impact energy to be imparted tothe sample being processed. The same spring-constant selection appliesto the selection of the resilient material for other (non-coil spring)embodiments. In addition, the coil compression springs can each be madeof a coiled element having a circular or other (e.g., rectangular)cross-sectional shape, in a helically cylindrical or other (e.g.,helical/spiral) configuration, and having uniform/even or variedlongitudinal spacing.

Turning now to the drawing figures, FIG. 1-3 show a homogenizing system,including a homogenizer 10, a tube 20, a sample 30, and an activegrinding media 40, according to an example embodiment. In particular,the homogenizer 10 includes a tube holder that is holding four sampletubes 20 (typical homogenizer holds one or multiple), with one of thetubes holding a sample 30 and an active grinding media 40. Thehomogenizer 10, tubes 20, and sample 30 can be of any conventional type,as defined above. The homogenizer 10 operates to generates anoscillatory stroke (as indicated by the linear double-headed arrow)having a stroke length (i.e., oscillatory amplitude or travel distance)12, which is the same as the tube oscillation travel. And the tubes 20each have a diameter (inner/chamber) 22 and a length (inner/chamber) 24,with the tube size selected for the particular sample to be processed.The tube length 24 is defined by the two opposite tube ends (oneintegral end and one endcap) 26. In typical embodiments, the homogenizerstroke length 12 is the same as or greater than the tube length 24 forgood results, though the stroke length can be shorter in otherembodiments.

The active grinding media 40 includes a grinding body in the form of acoil compression spring 42 made of a resilient material (e.g., springsteel). The spring body 42 includes a helically coiled element that isannular (e.g., hollow cylinder) and has an axial orientation, withannular end impact surfaces 44 (with a central compressible portionbetween them) that contact the tube ends 26 and the sample 30 duringuse, and with a central-bore flow-through opening 46 through which thesample 30 passes during use. The collapsible/compressible helical coilsegments of the spring body 42 have a uniform longitudinal spacing andhave a uniform radius. The structural features of the spring body 42 canbe selected to provide the functionality and benefits described above.

The end impact surfaces 44 are at the axially opposite ends of thespring body 42 and include the annular cross-sectional surface area ofthe spring body ends (e.g., the respective outer/last coil segments ofthe helically coiled element). Also, the exposed surface area of theintermediate helical coil segments (between the ends of the spring body42) define additional impact surfaces that contact the sample 30 duringprocessing. Furthermore, the internal flow-through opening 46 of thespring body 42 includes the central annular space defined by thehelically coiled element. Also, the gaps between the intermediatehelical coil segments of the spring body 42 define additionalflow-through openings for the sample 30 during processing (with theseadditional flow-through openings laterally/radially connecting theinternal flow-through opening 46 to the exterior of the spring body 42to form a circuitous flow path for increased flow and sampledisruption).

The spring body 42 is elongate so that it oscillates within the tube 20in a generally coaxial manner to enable good flow-through of the sample30 through its internal axial opening 46 and is mechanically constrainedfrom displacement from such coaxial orientation. In particular, thespring body 42 has an axial length 48 that is the same as or greaterthan the tube diameter 24 in order to prevent it from reorienting to aperpendicular position with its axis perpendicular to the tube axisduring translation within the tube. For example, the axial length 48 ofthe spring body 42 can be proportionally greater than the tube diameter24 by about 100% to about 200%. Furthermore, the spring body 42 has amaximum width 50 that is sized proportionally to the tube diameter 22(for example, about 50% to about 80%) to promote primarily axialtranslational movement and minimize glancing impacts against the tubesidewalls.

FIGS. 4-13 show sequential positions of a processing system, includingthe tube 20, particles/pieces of the sample 30, and the active grindingmedia 40 of FIGS. 1-3 , during use in a homogenizing process accordingto an example embodiment. In particular, these figures show aprogression of sequential time steps for a complete cycle of oscillatingmotion, starting (Time 0) at the middle of a full speed cycle as thetube 20 is at the center of oscillatory motion 14. The indicated timesteps are representative and not limited to any specific time incrementsor total time period. And the directional arrows of the active media 40and the sample 30 have a length generally corresponding to velocitymagnitude. As a preliminary step, the sample and the active grindingmedia are loaded into the tube, the tube is then sealed (e.g., the capis secured on the tube open end), and the loaded tube is mounted to thehomogenizer to be ready for use.

In FIG. 4 (Time 0), the tube 20 is centered at the center of the motion14, the sample 30 is in an unprocessed state, and the active media 40 isin an unloaded state, with all these components traveling in a firstdirection.

In FIG. 5 (Time 1), the tube 20 has advanced past the center of motion14, while the active media 40 has moved farther than the tube 20 (due tothe higher acceleration and velocity of the active media 40, relative tothe selected homogenizer stroke speed of the tube 20) or the unprocessedsample 30 (due to the higher mass, acceleration, and velocity of theactive media 40). At this point in the motion cycle, the active media 40has just contacted the tube end 26.

In FIG. 6 (Time 2), the tube 20 has decelerated and is now at amomentary stop, while the momentum of the active media 40 hastransitioned (deformed) it into a loaded (compressed/charged) state. Inthis position, the active media 40 has impacted the sample 30 betweenthe tube end 26 and the active media, causing it to be reduced in size(fewer larger pieces have been processed into more smaller pieces) dueto the impact forces.

In FIG. 7 (Time 3), the active media 40 is releasing its stored energyand accelerating in the opposite second direction at a higher rate ofacceleration than the tube 20.

In FIG. 8 (Time 4), the unloaded active media 40 has accelerated morerapidly than the tube 20 in the opposite second direction and hasimpacted pieces of the sample 30 still traveling in the first direction,resulting in higher-velocity and higher-force impacts.

In FIG. 9 (Time 5), the unloaded active media 40 under high accelerationcontinues to travel more rapidly than the tube 20, causing additionalhigh-velocity impacts with the sample 30. Some pieces of the sample 30may have not been reduced at this point, as they were not impactedduring this cycle, but will be impacted and reduced on a future cycle.

In FIG. 10 (Time 6), the tube 20 is under deceleration and the activemedia 40 has just contacted the opposite end of the tube. Some pieces ofthe sample 30 may be located in the gaps between the collapsible coilsections of the active media.

In FIG. 11 (Time 7), the tube 20 has decelerated to zero and the activemedia 40 has transitioned (deformed) into a loaded state. Any pieces ofthe sample 30 that were located in the gaps between the collapsible coilsections of the active media are now crushed between the collapsiblecoil sections, further reducing the sample particle size.

In FIG. 12 (Time 8), the active media 40 is releasing its stored energyand accelerating back in the first direction. The accelerating activemedia 40 again causes high-velocity impacts during its traversal of thetube 20.

And in FIG. 13 (Time 9), the unloaded active media 40 has accelerateddue to its stored energy release and is again traveling at a velocityhigher than the tube 20.

FIGS. 14-26 each show an active grinding media according to variousrespective example embodiments. The active grinding media of theseembodiments can have the same or similar structure and function as theembodiment of FIGS. 1-13 , except as noted.

FIGS. 14 a-14 b show an active media 140 having two larger-diameter endportions and a smaller-diameter middle portion in an hourglassconfiguration. This provides a larger cross-sectional impact area forimpacts during processing use, including the end impact areas 144 a forimpacting the tube ends and the sample, and additionally includingintermediate impact areas 144 b for impacting the sample (but not thetube ends). This also promotes axial translation of the active media 140to reduce glancing impacts against the tube sidewalls.

Also, the helical coil segments can have a varied and/or evenlongitudinal spacing, for example those of the end and middle portionscan have a first uniform longitudinal spacing (pitch) and those ofconnecting/transitioning portions (between the end and middle portions)can have a second uniform longitudinal spacing. The portions that aretightly coiled together (with little/less longitudinal spacing) havemore mass than more loosely coiled portions, thereby increasing the massso as to impart higher forces during energy storage and discharging andduring impacting the sample.

In FIG. 15 shows an active media 240 that is similar to that of FIGS. 14a-14 b except with the middle portion having a greater axial length, theend portions having a shorter axial length. Also, the combined/totalaxial length being greater to enable providing a longer middle portionthat is tightly coiled for increased mass/forces, as has been noted.

FIG. 16 shows an active media 340 that is similar to that of FIG. 15except with the middle portion having a greater diameter, which allowslarger particles/pieces of unprocessed sample to pass through the activemedia component during traversal of the tube, and which provides theactive media with greater mass/forces.

FIG. 17 shows an active media 440 that is similar to that of FIG. 2except tighter longitudinal spacing of end and middle portions andlooser longitudinal spacing of connecting/transitioning portions.

FIG. 18 shows an active media 540 that is similar to that of FIG. 2except with an hourglass configuration (for increased impact surfacearea) and with the coiled element having a rectangular cross-sectionalshape.

FIG. 19 shows an active media 640 that is similar to that of FIG. 2except with a conical configuration (for increased impact surface area),with the coils having uniformly progressively smaller to larger diameterfrom end to end in a uniform-pitch helical spiral configuration.

FIG. 20 shows an active media 740 that is similar to that of FIG. 19except with a barrel configuration having two conical portions with themiddle portion having a larger diameter than the end portions. Otherembodiments have a barrel configuration with a curved side profileprovided by the coils having a non-uniformly progressively smaller orlarger diameter from end to end.

FIG. 21 shows an active media 840 that is similar to that of FIG. 2except with a rigid central component between the ends of two alignedcoil spring bodies. The spring bodies can be of any type describedherein, not just that of FIG. 2 . The rigid central component does notload/charge and unload/discharge, but it provides more mass forincreased impact forces. As such, the depicted rigid central componentis a band with an internal flow-through opening (annular space), thoughother embodiments can include other internal or external flow-throughopenings.

FIG. 22 shows an active media 940 that is similar to that of FIG. 19except with two rigid components (e.g., bands) at the ends of a coilspring body. The bands can be made of a heavier material than the springto provide the greater mass/weight and related benefits described above.

FIG. 23 shows an active media 1040 that is similar to that of FIG. 2except with two coaxially arranged coiled spring body portions havingdifferent diameters to provide for increased impact area and energycharge/discharge.

FIG. 24 shows an active media 1140 that is similar to that of FIG. 23except with two linearly arranged coiled spring body portions havingdifferent diameters to provide for increased impact area and energycharge/discharge.

FIGS. 25 and 26 show respective active media 1240 and 1340 that aresimilar to that of FIG. 2 except with a respective generally ellipticaland generally triangular cross-sectional shape. Other embodiments have aspheroid configuration with a circularly curved side profile.

The active grinding media can be of any embodiments disclosed herein,including variations thereof, or of other embodiments, including otherresiliently deformable, elongate, flow-through structures. In someembodiments the active media is in the form of other types of springelements (e.g., leaf springs), hard outside/end elements (for impacting)interconnected by resilient inner elements (for energy storage andrelease), and/or other designs, and the flow-through feature can beprovided by designs including hollow/sleeve, perforated, mesh, screen,grate, or another flow-through design arrangement. In other embodiments,the active media can be non-elongate, with an axial length less than thetube diameter, and with the tube including a track or guide system forengaging and guiding the active media along its oscillatory motion andmaintained in its intended orientation with its internal and/or externalpassageways axially aligned for optimal flow-through of the sample.

In still other embodiments, the tubes can be provided with their twoends (e.g., one integral end and one endcap) including an inner layermade of a resiliently deformable material to provide the energy storageand discharge effect to grinding media, and can be used with the activegrinding media and/or with conventional passive grinding media.

It is to be understood that this invention is not limited to thespecific devices, methods, conditions, or parameters described and/orshown herein, and that the terminology used herein is for the purpose ofdescribing particular embodiments by way of example only. Thus, theterminology is intended to be broadly construed and is not intended tobe limiting of the claimed invention. For example, as used in thespecification including the appended claims, the singular forms “a,”“an,” and “one” include the plural, the term “or” means “and/or,” andreference to a particular numerical value includes at least thatparticular value, unless the context clearly dictates otherwise. Inaddition, any methods described herein are not intended to be limited tothe sequence of steps described but can be carried out in othersequences, unless expressly stated otherwise herein.

While the invention has been shown and described in exemplary forms, itwill be apparent to those skilled in the art that many modifications,additions, and deletions can be made therein without departing from thespirit and scope of the invention as defined by the following claims.

What is claimed is:
 1. An active grinding media configured to homogenizean organic sample in a homogenizing tube using a high-speed laboratoryhomogenizer, the active grinding media comprising: a grinding bodyhaving two opposite ends defining oppositely facing impact surfaces andhaving an intermediate compressible portion that is between the two endsand made of a resiliently deformable material, wherein the grinding bodyis configured to fit inside the tube along with the sample so that, whenthe tube is subjected to a high-velocity, longitudinal, oscillatorymotion along a longitudinal axis of the tube during homogenizing use,the active grinding media travels in a first direction until a first oneof the end impact surfaces impacts a first end of the tube, in responsethe intermediate compressible portion deforms and stores a first energycharge as it decelerates and stops, in response the active grindingmedia accelerates in a second opposite direction under a firstdischarging force of the intermediate compressible portion toward anopposite second end of the tube until a second opposite one of the endimpact surfaces impacts the second end of the tube, in response theintermediate compressible portion deforms and stores a second energycharge as it decelerates and stops, and in response the active grindingmedia accelerates back in the first direction under a second dischargingforce of the intermediate compressible portion toward the first end ofthe tube to complete an oscillatory cycle, wherein the oscillatory cycleis repeated, and wherein during the oscillatory cycle the grinding bodyimpacts the sample at accelerations and increased velocities toefficiently homogenize the sample, wherein the active grinding mediabody is configured for constraint in an axial orientation relative tothe tube axis and within the tube, wherein the active grinding mediabody is elongate in the axial orientation, wherein the active grindingmedia body has a length that is 100 percent to 400 percent of an innerdiameter of the tube so that the active grinding media body ismaintained in the axial orientation during homogenizing use.
 2. Theactive grinding media of claim 1, wherein the active grinding media bodydefines at least one flow-through opening through which the samplepasses during the oscillatory motion of the active grinding media withinthe tube.
 3. The active grinding media of claim 2, wherein theflow-through opening is formed internally through the active grindingmedia body.
 4. The active grinding media of claim 1, wherein the activegrinding media body has a width that is smaller than the tube innerdiameter.
 5. The active grinding media of claim 4, wherein the activegrinding media body width is 50 percent to 80 percent of the tube innerdiameter.
 6. The active grinding media of claim 1, wherein the activegrinding media body is a coil compression spring.
 7. A processing systemcomprising, in combination, the active grinding media and the tube ofclaim
 1. 8. A method of using the active grinding media of claim 7 tohomogenize the sample, comprising: loading the sample and the activegrinding media into the tube, then sealing the tube; mounting the sealedtube containing the sample and the active grinding media to thehigh-speed laboratory homogenizer; and operating the high-speedlaboratory homogenizer through one or more of the oscillatory cyclesuntil the sample is homogenized.
 9. The method of claim 8, wherein thestep of operating the high-speed laboratory homogenizer includesselecting a speed setting of between 0.1 m/s and 6.0 m/s.
 10. An activegrinding media configured to homogenize an organic sample in ahomogenizing tube using a high-speed laboratory homogenizer thatgenerates a high-velocity longitudinal oscillatory motion, the activegrinding media comprising: a grinding body in the form of a coilcompression spring including helical coil segments in an annulararrangement, wherein the grinding body has two opposite ends, anintermediate compressible portion between the two ends, and aflow-through opening extending end-to-end therethrough, wherein the twoopposite ends are annular and formed by two outermost of the coilsegments and define oppositely facing impact surfaces, wherein theintermediate compressible portion is formed by one or more intermediateones of the coil segments between the two outermost coil segments and ismade of a resiliently deformable material, wherein the flow-throughopening extends internally through the annular grinding body to enablepassage therethrough of the sample during the oscillatory motion of theactive grinding media within the tube, wherein the grinding body isconfigured to fit inside the tube along with the sample so that, whenthe tube is subjected to the high-velocity, longitudinal, oscillatorymotion along a longitudinal axis of the tube during homogenizing use,the active grinding media travels in a first direction until a first oneof the end impact surfaces impacts a first end of the tube, in responsethe intermediate compressible portion deforms and stores a first energycharge as it decelerates and stops, in response the active grindingmedia accelerates in a second opposite direction under a firstdischarging force of the intermediate compressible portion toward anopposite second end of the tube until a second opposite one of the endimpact surfaces impacts the second end of the tube, in response theintermediate compressible portion deforms and stores a second energycharge as it decelerates and stops, and in response the active grindingmedia accelerates back in the first direction under a second dischargingforce of the intermediate compressible portion toward the first end ofthe tube to complete an oscillatory cycle, wherein the oscillatory cycleis repeated a set number of times, and wherein during the oscillatorycycle the grinding body impacts the sample at accelerations andincreased velocities to efficiently homogenize the sample, wherein theactive grinding media body is configured for constraint in an axialorientation relative to the tube axis and within the tube, wherein theactive grinding media body defines the flow-through opening in the axialorientation, wherein the active grinding media body has a length that is100 percent to 400 percent of an inner diameter of the tube so that theactive grinding media body and the flow-through opening are maintainedin the axial orientation during homogenizing use.
 11. The activegrinding media of claim 10, wherein the active grinding media body has awidth that is smaller than the tube inner diameter.
 12. The activegrinding media of claim 11, wherein the active grinding media body widthis 50 percent to 80 percent of the tube inner diameter.
 13. The activegrinding media of claim 10, wherein the coil compression spring ishollow so the flow-through opening is unobstructed to enable passagetherethrough of the sample during the oscillatory motion of the activegrinding media within the tube.
 14. A processing system comprising, incombination, the active grinding media and the tube of claim
 10. 15. Amethod of using the active grinding media of claim 10 to homogenize thesample, comprising: loading the sample and the active grinding mediainto the tube, then sealing the tube; mounting the sealed tubecontaining the sample and the active grinding media to the high-speedlaboratory homogenizer; and operating the high-speed laboratoryhomogenizer through one or more of the oscillatory cycles until thesample is homogenized.
 16. The method of claim 15, wherein the step ofoperating the high-speed laboratory homogenizer includes generating ahomogenizer stroke length that is the same as or greater than a lengthof the tube.
 17. The method of claim 15, wherein the step of operatingthe high-speed laboratory homogenizer includes selecting a speed settingof between 0.1 m/s and 6.0 m/s.